k8temp.c revision 281dfd0b6ed5403f5b9b1669f2a37a4f8cfc11c1 
1/*
2 * k8temp.c - Linux kernel module for hardware monitoring
3 *
4 * Copyright (C) 2006 Rudolf Marek <r.marek@assembler.cz>
5 *
6 * Inspired from the w83785 and amd756 drivers.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21 * 02110-1301 USA.
22 */
23
24#include <linux/module.h>
25#include <linux/init.h>
26#include <linux/slab.h>
27#include <linux/jiffies.h>
28#include <linux/pci.h>
29#include <linux/hwmon.h>
30#include <linux/hwmon-sysfs.h>
31#include <linux/err.h>
32#include <linux/mutex.h>
33#include <asm/processor.h>
34
35#define TEMP_FROM_REG(val)	(((((val) >> 16) & 0xff) - 49) * 1000)
36#define REG_TEMP	0xe4
37#define SEL_PLACE	0x40
38#define SEL_CORE	0x04
39
40struct k8temp_data {
41	struct device *hwmon_dev;
42	struct mutex update_lock;
43	const char *name;
44	char valid;		/* zero until following fields are valid */
45	unsigned long last_updated;	/* in jiffies */
46
47	/* registers values */
48	u8 sensorsp;		/* sensor presence bits - SEL_CORE, SEL_PLACE */
49	u32 temp[2][2];		/* core, place */
50	u8 swap_core_select;    /* meaning of SEL_CORE is inverted */
51	u32 temp_offset;
52};
53
54static struct k8temp_data *k8temp_update_device(struct device *dev)
55{
56	struct k8temp_data *data = dev_get_drvdata(dev);
57	struct pci_dev *pdev = to_pci_dev(dev);
58	u8 tmp;
59
60	mutex_lock(&data->update_lock);
61
62	if (!data->valid
63	    || time_after(jiffies, data->last_updated + HZ)) {
64		pci_read_config_byte(pdev, REG_TEMP, &tmp);
65		tmp &= ~(SEL_PLACE | SEL_CORE);	/* Select sensor 0, core0 */
66		pci_write_config_byte(pdev, REG_TEMP, tmp);
67		pci_read_config_dword(pdev, REG_TEMP, &data->temp[0][0]);
68
69		if (data->sensorsp & SEL_PLACE) {
70			tmp |= SEL_PLACE;	/* Select sensor 1, core0 */
71			pci_write_config_byte(pdev, REG_TEMP, tmp);
72			pci_read_config_dword(pdev, REG_TEMP,
73					      &data->temp[0][1]);
74		}
75
76		if (data->sensorsp & SEL_CORE) {
77			tmp &= ~SEL_PLACE;	/* Select sensor 0, core1 */
78			tmp |= SEL_CORE;
79			pci_write_config_byte(pdev, REG_TEMP, tmp);
80			pci_read_config_dword(pdev, REG_TEMP,
81					      &data->temp[1][0]);
82
83			if (data->sensorsp & SEL_PLACE) {
84				tmp |= SEL_PLACE; /* Select sensor 1, core1 */
85				pci_write_config_byte(pdev, REG_TEMP, tmp);
86				pci_read_config_dword(pdev, REG_TEMP,
87						      &data->temp[1][1]);
88			}
89		}
90
91		data->last_updated = jiffies;
92		data->valid = 1;
93	}
94
95	mutex_unlock(&data->update_lock);
96	return data;
97}
98
99/*
100 * Sysfs stuff
101 */
102
103static ssize_t show_name(struct device *dev, struct device_attribute
104			 *devattr, char *buf)
105{
106	struct k8temp_data *data = dev_get_drvdata(dev);
107
108	return sprintf(buf, "%s\n", data->name);
109}
110
111
112static ssize_t show_temp(struct device *dev,
113			 struct device_attribute *devattr, char *buf)
114{
115	struct sensor_device_attribute_2 *attr =
116	    to_sensor_dev_attr_2(devattr);
117	int core = attr->nr;
118	int place = attr->index;
119	int temp;
120	struct k8temp_data *data = k8temp_update_device(dev);
121
122	if (data->swap_core_select && (data->sensorsp & SEL_CORE))
123		core = core ? 0 : 1;
124
125	temp = TEMP_FROM_REG(data->temp[core][place]) + data->temp_offset;
126
127	return sprintf(buf, "%d\n", temp);
128}
129
130/* core, place */
131
132static SENSOR_DEVICE_ATTR_2(temp1_input, S_IRUGO, show_temp, NULL, 0, 0);
133static SENSOR_DEVICE_ATTR_2(temp2_input, S_IRUGO, show_temp, NULL, 0, 1);
134static SENSOR_DEVICE_ATTR_2(temp3_input, S_IRUGO, show_temp, NULL, 1, 0);
135static SENSOR_DEVICE_ATTR_2(temp4_input, S_IRUGO, show_temp, NULL, 1, 1);
136static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
137
138static DEFINE_PCI_DEVICE_TABLE(k8temp_ids) = {
139	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB_MISC) },
140	{ 0 },
141};
142
143MODULE_DEVICE_TABLE(pci, k8temp_ids);
144
145static int is_rev_g_desktop(u8 model)
146{
147	u32 brandidx;
148
149	if (model < 0x69)
150		return 0;
151
152	if (model == 0xc1 || model == 0x6c || model == 0x7c)
153		return 0;
154
155	/*
156	 * Differentiate between AM2 and ASB1.
157	 * See "Constructing the processor Name String" in "Revision
158	 * Guide for AMD NPT Family 0Fh Processors" (33610).
159	 */
160	brandidx = cpuid_ebx(0x80000001);
161	brandidx = (brandidx >> 9) & 0x1f;
162
163	/* Single core */
164	if ((model == 0x6f || model == 0x7f) &&
165	    (brandidx == 0x7 || brandidx == 0x9 || brandidx == 0xc))
166		return 0;
167
168	/* Dual core */
169	if (model == 0x6b &&
170	    (brandidx == 0xb || brandidx == 0xc))
171		return 0;
172
173	return 1;
174}
175
176static int k8temp_probe(struct pci_dev *pdev,
177				  const struct pci_device_id *id)
178{
179	int err;
180	u8 scfg;
181	u32 temp;
182	u8 model, stepping;
183	struct k8temp_data *data;
184
185	data = devm_kzalloc(&pdev->dev, sizeof(struct k8temp_data), GFP_KERNEL);
186	if (!data)
187		return -ENOMEM;
188
189	model = boot_cpu_data.x86_model;
190	stepping = boot_cpu_data.x86_mask;
191
192	/* feature available since SH-C0, exclude older revisions */
193	if ((model == 4 && stepping == 0) ||
194	    (model == 5 && stepping <= 1))
195		return -ENODEV;
196
197	/*
198	 * AMD NPT family 0fh, i.e. RevF and RevG:
199	 * meaning of SEL_CORE bit is inverted
200	 */
201	if (model >= 0x40) {
202		data->swap_core_select = 1;
203		dev_warn(&pdev->dev, "Temperature readouts might be wrong - "
204			 "check erratum #141\n");
205	}
206
207	/*
208	 * RevG desktop CPUs (i.e. no socket S1G1 or ASB1 parts) need
209	 * additional offset, otherwise reported temperature is below
210	 * ambient temperature
211	 */
212	if (is_rev_g_desktop(model))
213		data->temp_offset = 21000;
214
215	pci_read_config_byte(pdev, REG_TEMP, &scfg);
216	scfg &= ~(SEL_PLACE | SEL_CORE);	/* Select sensor 0, core0 */
217	pci_write_config_byte(pdev, REG_TEMP, scfg);
218	pci_read_config_byte(pdev, REG_TEMP, &scfg);
219
220	if (scfg & (SEL_PLACE | SEL_CORE)) {
221		dev_err(&pdev->dev, "Configuration bit(s) stuck at 1!\n");
222		return -ENODEV;
223	}
224
225	scfg |= (SEL_PLACE | SEL_CORE);
226	pci_write_config_byte(pdev, REG_TEMP, scfg);
227
228	/* now we know if we can change core and/or sensor */
229	pci_read_config_byte(pdev, REG_TEMP, &data->sensorsp);
230
231	if (data->sensorsp & SEL_PLACE) {
232		scfg &= ~SEL_CORE;	/* Select sensor 1, core0 */
233		pci_write_config_byte(pdev, REG_TEMP, scfg);
234		pci_read_config_dword(pdev, REG_TEMP, &temp);
235		scfg |= SEL_CORE;	/* prepare for next selection */
236		if (!((temp >> 16) & 0xff)) /* if temp is 0 -49C is unlikely */
237			data->sensorsp &= ~SEL_PLACE;
238	}
239
240	if (data->sensorsp & SEL_CORE) {
241		scfg &= ~SEL_PLACE;	/* Select sensor 0, core1 */
242		pci_write_config_byte(pdev, REG_TEMP, scfg);
243		pci_read_config_dword(pdev, REG_TEMP, &temp);
244		if (!((temp >> 16) & 0xff)) /* if temp is 0 -49C is unlikely */
245			data->sensorsp &= ~SEL_CORE;
246	}
247
248	data->name = "k8temp";
249	mutex_init(&data->update_lock);
250	pci_set_drvdata(pdev, data);
251
252	/* Register sysfs hooks */
253	err = device_create_file(&pdev->dev,
254			   &sensor_dev_attr_temp1_input.dev_attr);
255	if (err)
256		goto exit_remove;
257
258	/* sensor can be changed and reports something */
259	if (data->sensorsp & SEL_PLACE) {
260		err = device_create_file(&pdev->dev,
261				   &sensor_dev_attr_temp2_input.dev_attr);
262		if (err)
263			goto exit_remove;
264	}
265
266	/* core can be changed and reports something */
267	if (data->sensorsp & SEL_CORE) {
268		err = device_create_file(&pdev->dev,
269				   &sensor_dev_attr_temp3_input.dev_attr);
270		if (err)
271			goto exit_remove;
272		if (data->sensorsp & SEL_PLACE) {
273			err = device_create_file(&pdev->dev,
274					   &sensor_dev_attr_temp4_input.
275					   dev_attr);
276			if (err)
277				goto exit_remove;
278		}
279	}
280
281	err = device_create_file(&pdev->dev, &dev_attr_name);
282	if (err)
283		goto exit_remove;
284
285	data->hwmon_dev = hwmon_device_register(&pdev->dev);
286
287	if (IS_ERR(data->hwmon_dev)) {
288		err = PTR_ERR(data->hwmon_dev);
289		goto exit_remove;
290	}
291
292	return 0;
293
294exit_remove:
295	device_remove_file(&pdev->dev,
296			   &sensor_dev_attr_temp1_input.dev_attr);
297	device_remove_file(&pdev->dev,
298			   &sensor_dev_attr_temp2_input.dev_attr);
299	device_remove_file(&pdev->dev,
300			   &sensor_dev_attr_temp3_input.dev_attr);
301	device_remove_file(&pdev->dev,
302			   &sensor_dev_attr_temp4_input.dev_attr);
303	device_remove_file(&pdev->dev, &dev_attr_name);
304	return err;
305}
306
307static void k8temp_remove(struct pci_dev *pdev)
308{
309	struct k8temp_data *data = pci_get_drvdata(pdev);
310
311	hwmon_device_unregister(data->hwmon_dev);
312	device_remove_file(&pdev->dev,
313			   &sensor_dev_attr_temp1_input.dev_attr);
314	device_remove_file(&pdev->dev,
315			   &sensor_dev_attr_temp2_input.dev_attr);
316	device_remove_file(&pdev->dev,
317			   &sensor_dev_attr_temp3_input.dev_attr);
318	device_remove_file(&pdev->dev,
319			   &sensor_dev_attr_temp4_input.dev_attr);
320	device_remove_file(&pdev->dev, &dev_attr_name);
321}
322
323static struct pci_driver k8temp_driver = {
324	.name = "k8temp",
325	.id_table = k8temp_ids,
326	.probe = k8temp_probe,
327	.remove = k8temp_remove,
328};
329
330module_pci_driver(k8temp_driver);
331
332MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>");
333MODULE_DESCRIPTION("AMD K8 core temperature monitor");
334MODULE_LICENSE("GPL");
335